sap

Sap is distinct from latex ...; it is a separate substance, separately produced, and with different components and functions.

— Wikipedia

introduction

sap (not to be confused with Systeme, Anwendungen und Produkte in der Datenverarbeitung) is a document typesetting/preparation system similar in concept to LaTeX (and derivatives), with the following major differences:

1. it is not from 1978 (TeX), 1984 (LaTeX), or 1994 (LaTeX2e)
2. it is not a glorified macro system
3. it is not a fragile amalgamation of packages all trying not to step on each others' toes
4. the programming 'metalanguage' is familiar (and sane)

This is currently a work-in-progress, so features are quite limited. An incomplete list of features can be found at the bottom of this document.

goals

The eventual goal of this project is to completely replace LaTeX as my document typesetting system. To this end, there are some "big features" that will be implemented eventually:

1. Graphics support — at least the (very very) basic features of PGF/TikZ
2. Full document metaprogramming (freely manipulating text)
3. Some basic level of typesetting mathematical expressions
4. Some level of bibliography/referencing support
5. ...?

non-goals

Non-goals are split into two categories: things I can't do because this is a one-person effort, and things I won't do because they are not in the scope of this project. For the former, pull requests are very appreciated (:

can't

These are mostly because (a) I won't be writing documents in any of these languages, and (b) I don't know any of these languages.

1. Right-to-left languages
2. "Complex" latin scripts, eg. Vietnamese
3. "Complex" non-latin scripts, eg. Arabic, Urdu

won't

While I appreciate the vast ecosystem that LaTeX has, having any kind of compatibility is simply not possible for obvious reasons.

1. Any sort of TeX/LaTeX compatibility
2. Graphical parity with LaTeX
3. Non-OpenType font support (eg. Type1)
4. Generating LaTeX source as an output

current featureset

This also acts as a sort of TODO; as time goes on completed features may be removed from this list if they are deemed "trivial".

• OpenType font (otf/ttf) loading and embedding
• Embedded font subsetting (both TrueType and CFF)
• Variable font support
• Further size optimisation for embedded fonts
• Glyph positioning (OpenType GPOS, lookups 1, 2, 7, 8, 9)
• Glyph substitutions (incl. ligatures) (OpenType GSUB, lookups 1, 2, 4, 5, 6, 7)
• Truetype/AAT kern table
• AAT tables (kerx, morx)
• More advanced typography support (BASE, MATH, JSTF)
• Text extraction (eg. copy/paste) support — ToUnicode table
• Unicode substitution (eg. codepoint (de)composition)
• Vertical writing
• Very very (very very...) basic paragraph layout, linebreaking, and pagination
• Literally any metalanguage

alternatives

But what about <insert_tool_here>?

• (g)roff: the language (doesn't seem) powerful enough, seems to require strange things to use unicode, and the syntax is too terse.
• patoline: development seems slow/abandoned, basic things don't work (eg. copying text)
• html/css: no. just no.

license

sap is licensed under the Apache License version 2.0. utf8proc and miniz are licensed under their respective licenses.